A gas bag known from U.S. Pat. No. 5,464,250 has a zigzag-shaped section of fabric, sewn at the edge sections with the fabric layers, which section acts as a spacer. The effect of this spacer is to prevent the gas bag from bulging excessively, i.e. from becoming too thick between its edges. Other types of spacers are so-called tethers, the ends of which are sewn to the fabric layers and limit the spacing locally. The fitting of spacers is a very expensive and elaborate procedure and hinders inversion of the gas bag after sewing. The arrangement of the spacers is therefore very complicated, and for manufacturing reasons the spacers cannot be arranged at any site whatever. On the other hand, the inflated gas bags would become unnecessarily thick without spacers, which presents problems. Optimum restraint calls to some extent for no extreme thickness of the gas bag, so that an unnecessarily large amount of gas would be needed to completely fill the gas bag. Moreover, as the thickness becomes greater, the risk of the occupants being struck by the deploying gas bag also increases.
For this reason, side gas bags (known as "window bags") are produced that have numerous, parallel, narrow chambers. Here, the fabric layers are interwoven in one piece on the outside contour of the gas bag and between the chambers. The numerous chambers, in some cases elongated and having a low cross-section, can increase the time to inflate the gas bag. Furthermore, these require precise delivery of the gas to the chambers themselves, e.g. by means of a gas lance which extends along the roof frame.